Arduino wifi shield

Hi everyone. I'm building a hovercraft and I want to remotely control it. I thought Arduino is a fun way to do it cause I already have a Arduino board. though I'm not an Arduino pro(more like a noob) so please speak English ;) I am thinking a wifi shield would do the trick but..... How does a wifi shield work? Does is set it's own signal? Or does it have to connect to an existing network? Is it a good way to control a hovercraft or is it too slow? You would help me a lot. Thanks in advance

The wifi shield must connect to a router. It works only as a station, not as an access point.

Is ad hoc an option?

Silvanor: Is ad hoc an option?

Not the last time i checked. :(

The problem is the wifi shield will not connect to a device that does not transmit a SSID, and devices on an ad hoc network don't.